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Oral Tumors, Benign 713

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A B C
ORAL TUMORS, BENIGN A, Total mandibulectomy: preoperative image of a cat with a right mandibular amyloid-
producing odontogenic tumor (APOT), which is a benign but locally aggressive neoplasm. B, Total mandibulectomy:
intraoperative image shows resected right mandible from same cat. C, Total mandibulectomy: postoperative image of
the same cat presenting several months later for a recheck shows excellent healing of the surgical site and no tumor
recurrence. (Copyright Dr. Alexander M. Reiter, University of Pennsylvania.)

tissue) usually prevents local recurrence likelihood of wound dehiscence in oral • Right or left total mandibulectomy (previ-
of benign lesions. For tumors such as surgery. ously called hemimandibulectomy) and
acanthomatous ameloblastoma, wide resec- maxillectomy surgeries carry with them
tion (removal of the mass and 1-2 cm of Recommended Monitoring the potential for profuse bleeding. Blood
surrounding tissue) is indicated. Repeat oral exam, including head/neck lymph type and cross-matching may be warranted
• When surgical excision is not an option, node palpation, to monitor for recurrence at preoperatively.
efforts should be made to decrease the rate of 6-month intervals.
growth (e.g., radiation therapy) and provide Technician Tips
relief from discomfort (extraction of teeth PROGNOSIS & OUTCOME • Technicians are on the frontline of identify-
impinging on the tumor, administration of ing oral tumors during professional dental
pain medications). • Prognosis is excellent with benign tumors cleanings. Do a complete oral exam on each
if they are amenable to complete surgical anesthetized patient, including the sublingual
Acute General Treatment resection or respond to radiation therapy. area and tonsils. Bring all identified oral
• Removal of a circumscribed mass to the • When clients are reluctant to pursue surgery, masses to the attention of the clinician for
normal level of the surrounding gingiva radiation therapy has been documented to possible biopsy during the same anesthetic
often serves as an adequate biopsy but may provide a good long-term clinical outcome episode.
not prevent local recurrence. Peripheral for treatment of canine acanthomatous • Provide as much information as possible on
odontogenic fibromas may recur if the associ- ameloblastoma. histopathologic evaluation forms. Include size
ated tooth/teeth and the inciting gingival (in three dimensions), surface characteristics
connective tissue/periodontal ligament have PEARLS & CONSIDERATIONS (ulcerated, smooth, verrucous), complete
not been removed. history, and specific location of tumors.
• Incisional biopsies of large masses are Comments
warranted to provide information before • For larger oral masses, start with an incisional Client Education
considering radical surgery. biopsy to obtain more information before • Complete surgical removal of oral tumors
definitive resection. Biopsy results help deter- provides the best long-term prognosis.
Chronic Treatment mine the required extent of definitive surgical Clinicians should advise new pet owners to
• Depending on biopsy result and tumor resection and other treatment options. When acclimate puppies and kittens to periodic
extent, surgery or radiation therapy may submitting excisional biopsies, clinicians exam of the oral cavity (as well as routine
be good long-term options. should request that the pathologist evaluate at-home dental care).
• Intralesional chemotherapy has been reported margins for presence of neoplastic cells. Clean • Animals adapt remarkably well after radical
to be successful for treatment of some benign margins according to histologic exam do not resection of oral tumors, and altered cosmesis
tumors (e.g., acanthomatous ameloblastoma). rule out the possibility of recurrence, but is usually well accepted by owners if enough
Systemic chemotherapy may be used as an animals with clean margins do have a better function can be restored to allow for inde-
adjunctive therapy but is rarely effective by long-term prognosis. pendent eating and drinking. Clients should
itself against most oral tumors. • Dental radiography is invaluable for be shown before and after pictures of similar
• Radiation therapy offers excellent long-term providing diagnostic and treatment plan- surgical cases to ensure their understanding
control for treatment of acanthomatous ning information for oral tumors. Benign of cosmetic changes.
ameloblastoma, but malignant tumors may tumors tend to displace teeth that often
develop in the irradiated area in 3.5%-12.5% remain firmly seated, whereas aggressive SUGGESTED READING
of dogs. tumors cause root and alveolar bone resorp- Goldschmidt SL, et al: Clinical characterization
tion, which may manifest as very mobile of canine acanthomatous ameloblastoma (CAA)
Possible Complications (floating) teeth. Benign tumors may have a in 263 dogs and the influence of postsurgical
• Recurrence of primary tumor smooth layer of reactive bone surrounding histopathological margin on local recurrence. J
• Intraoperative or postoperative bleeding the neoplastic tissue, whereas a malignant Vet Dent 34(4):241-247, 2017.
• Dehiscence of the surgical site: use of elec- tumor often exhibits destruction of cortical AUTHOR: John R. Lewis, VMD, FAVD, DAVDC
trocautery may obscure histologic exam of bone with formation of a classic sunburst EDITOR: Alexander M. Reiter, DVM, Dr.med.vet.,
margins of excised tissue and increase the appearance. DAVDC, DEVDC

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